Effects of Lonicera japonica Flower Bud Extract on Citrobacter rodentium-Induced Digestive Tract Infection.

Masaaki Minami,Toshiaki Makino

doi:10.3390/medicines7090052

Abstract

Background: Although antibiotic therapy is currently a gold standard for bacterial infections, it is not used for severe diseases like enterohemorrhagic Escherichia coli, in which the Shiga toxin is overproduced by antibiotic action. The Lonicera japonica flower bud (LJF) is an herbal component used against purulent diseases in traditional Japanese and Chinese medicine. We investigated the effects of LJF extract (LJFE) on Citrobacter rodentium-induced digestive tract infection in a mouse model. Methods: Citrobacter rodentium and LJFE were orally administered to C57BL/6 mice. The survival rate and bacterial colonization in the large intestine, mesenteric lymph node, and blood of mice were evaluated. Cytokines secreted from intraperitoneal macrophages of LJFE-treated mice were measured using ELISA. Moreover, the phagocytic activity of intraperitoneal macrophages against Citrobacter rodentium was compared between LJFE- or chlorogenic acid (CGA)-treated mice. Results: LJFE significantly increased the survival rate and decreased Citrobacter rodentium colonization in mice. Moreover, the values of tumor necrosis factor-α, interleukin-1β, and interferon-γ secreted from macrophages were increased following LJFE treatment. While macrophages of LJFE-treated mice showed a significant phagocytic activity, macrophages of CGA-treated mice only showed a phagocytic tendency. Conclusions: LJF may be useful for treating Citrobacter rodentium-induced digestive tract infection.

Highlights

Bacterial infections of the gastrointestinal tract, including pathogenic Escherichia coli O157 infections, are important communicable diseases because they infect many people and include deaths [1,2].Even though antibiotic treatment is the gold standard for bacterial infections, sensitivity to antibiotics has decreased due to the spread of multidrug-resistant bacteria, such as extended spectrum β-lactamaseand carbapenemase-producing bacteria [3,4]
From the results of this study, we showed that Lonicera japonica flower bud extract (LJFE) treatment improved the survival rate; suppressed bacterial theshowed large intestine, lymph nodes, and blood; From the results colonization of this study,inwe that LJFE mesenteric treatment improved the survival rate; slightly increased the serum levels of inflammatory cytokines; induced the phagocytic suppressed bacterial colonization in the large intestine, mesenteric lymph nodes, and blood;activity slightly of peritoneal elevated inflammatory cytokine from theseofperitoneal increased the macrophages; serum levels ofand inflammatory cytokines; induced the secretion phagocytic activity peritoneal macrophages in Citrobacter rodentium-infected mice
Our results showed that the phagocytic the possibility that LJFE exerts a strong stimulatory effect on immune cells, such as intraperitoneal activity of intraperitoneal macrophages collected from was increased

Summary

Introduction

Bacterial infections of the gastrointestinal tract, including pathogenic Escherichia coli O157 infections, are important communicable diseases because they infect many people and include deaths [1,2].Even though antibiotic treatment is the gold standard for bacterial infections, sensitivity to antibiotics has decreased due to the spread of multidrug-resistant bacteria, such as extended spectrum β-lactamaseand carbapenemase-producing bacteria [3,4]. Bacterial infections of the gastrointestinal tract, including pathogenic Escherichia coli O157 infections, are important communicable diseases because they infect many people and include deaths [1,2]. The use of antibiotic therapy is avoided for some diseases. Lonicera japonica is one of the popular medicinal plants among honeysuckles, and its dried flower bud (LJF) is used as an antipyretic and detoxification agent in traditional Chinese medicine (TCM) [6]. Antibiotic therapy is currently a gold standard for bacterial infections, it is not used for severe diseases like enterohemorrhagic Escherichia coli, in which the Shiga toxin is overproduced by antibiotic action. The Lonicera japonica flower bud (LJF) is an herbal component used against purulent diseases in traditional Japanese and Chinese medicine. We investigated the effects of LJF extract (LJFE) on Citrobacter rodentium-induced digestive tract infection in a mouse model

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Discussion

Conclusion